The present invention relates to a differential pressure sensor and, in particular, to a pressure sensor provided with a dual level of overrange protection in order to permit high sensitivity in the measurable range while providing reliable overrange protection against pressure differentials greatly exceeding the measurable range.
The conflicting requirements of high sensitivity and reliable overrange protection have long been a problem in the design of differential pressure sensors. In typical applications, high sensitivity requires the conversion of pressure differentials into substantial displacements whereas overrange protection requires sturdy components resistant to substantial displacement. Numerous proposals have been advanced for compromising these inconsistent requirements but none have proven completely satisfactory. Accordingly, there is a need for a new approach in the design of such sensors which can simultaneously provide high sensitivity and reliable protection.